Which of these changes is a chemical change?

Examples are burning, rusting, rotting, cooking etc.

Explanation:

A chemical change is a change accompanied by a change in the chemical composition of the substances involved. Chemical changes are irreversible changes that brings about rearrangement of the atoms of one or more substances and a change in their chemical composition. An entirely new substance is usually formed when chemical reaction takes place.

In a chemical reaction a chemical change occur and a new product is formed. In a chemical reaction heat is usually released or absorbed from the surrounding. Examples of chemical change are burning of wood, rusting, cooking and rotting. Like the case of burning of wood you will notice that an entirely new substance is formed that is very different from the initial substances that took part in the reaction.

A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding.